The Atlas Sound DT12 1' x 2' drop in speaker system simplifies loudspeaker installation by providing an all in one speaker package in acoustic ceiling grids. The system includes the speaker / transformer, enclosure, and grille with an external mounted tap selector switch. The compact 2-unit master pack is designed to save warehouse space. You will enjoy clear, crisp paging and background music from the installation friendly DT12 without compromising building cosmetics